There are a number of major problems encountered in present day tampons, which are basically constructed of cellulose materials such as rayon and cotton. These tampons currently leave linting fibers and can leave fibrous fragments. Because of the cellulose composition insertion can be uncomfortable. Once a tampon is inserted there is uneven expansion, and if there is a low flow of vaginal fluids the tampon can be stiff and uncomfortable for the user. If there is a high flow of vaginal fluids the tampon can leak. In an attempt to solve the high fluid problem super absorbent tampons have been sold in the market. A problem with these absorbents are that they are large and uncomfortable. Another significant problem with the prior art tampons is that on removal the tampon can be difficult and painful to remove. Furthermore a tampon can be messy upon removal and the vaginal cavity can be left with residue which can promote harmful bacteria growth.
Rayon, a wood pulp derivative that is commonly chlorine-bleached, is more absorbent than cotton and is a commonly used material in tampons. Rayon and rayon-cotton blend fibers are widely used in the manufacture of tampons. Dioxin, found throughout the environment in varying levels, collects in the fatty tissues of animals including humans and has been found in rayon products. Considering a woman may use as many as 11,000 tampons in her lifetime, she may be subjecting herself to additional dioxin exposure.
Rayon itself may pose another risk. Results of a study recently published in Infectious Diseases in Obstetrics and Gynecology suggest that the use of all-cotton tampons may reduce the risk of Toxic Shock Syndrome (TSS)when compared with rayon and rayon-blend tampons. The study included 20 varieties of tampons, a polyurethane contraceptive sponge, a latex diaphragm and a polymer menstrual collection cup. All-cotton tampons did not produce the dangerous TSS toxin, Staphylococcus aureus, while all other varieties containing rayon amplified production of the toxin TSS-TI. While this study appears to be shaded toward cotton tampons, cotton tampons also have been shown to produce TSS and have the problems inherent with all cellulose material, namely; Tinting fibers provide a haven for bacteria as well as leaving fibrous fragments, insertion can be uncomfortable, uneven expansion, with low flow cellulose material is stiff and uncomfortable, with high flow cellulose material can leak as a portion of the packing becomes hydrated and the rest leaks down the string staining the undergarment, it can be difficult and painful to remove, can be messy upon removal, super absorbents are large and uncomfortable and cellulose material has numerous safety concerns.
The prior art discloses examples of tampons of all kinds of material and shapes to numerous to note but several examples of prior art show or indicate the use of tampons using polyvinyl acetal in their construction.
U.S. Pat. No. 4,098,728 issued Jul. 4, 1978 discloses the use of polyvinyl acetal for medical usage with a fast wicking and high liquid holding capacity.
U.S. Pat. No. 5,071,648, issued on Dec. 10, 1991 discloses a polyvinyl acetal material with a complex of iodine which forms a sponge releasing controlled amounts of iodine sufficient to kill germ cells with minimum toxicity to the surrounding tissue. The patent indicates inferentially in a list of products that polyvinyl acetal iodinized material may be utilized as a tampon.
U.S. Pat. No. 5,744,150 issued on Apr. 28, 1998 discloses a method for producing an antimicrobial iodine polyvinyl acetal sponge which is soaked in a aqueous bath of 20% to 70% triethylene glycol. The complexed sponge materials are noted as being employed in a list of goods including tampons.
U.S. Pat. No. 5,811,471, issued Sep. 22, 1998 discloses a polyvinyl acetal polymer which has a germicidal disinfectant dye bound thereto which is used as a tampon. As noted in the patent, tampons constructed of polyvinyl acetal might best use a somewhat denser, highly absorbent grade of the material. The number and size of the air bubbles in the PVA material controls these properties. Polyvinyl acetal is already used in nasal packings and other surgical packings and the same grade of PVA can be used for those applications with the invention noted in that patent.
Materials that are closely related chemically to the polyvinyl acetate-alcohol-acetal porous bodies of this invention have been used in a variety of biologically related applications. The following uses of related materials is considered exemplary and illustrative of such uses. Tan, J. H.,; et al, (Radiation Research, vol. 124, no.1, p. 43-9, October 1990) implanted a polyvinyl alcohol sponge disc in the subcutis of the thorax. A separating agent which includes a polyvinyl acetal resin having open cell structure and an average pore size of from about 10 to about 1000 micrometers has been described in U.S. Pat. No. 5,085,781 issued Feb. 4, 1992. U.S. Pat. No. 5,370,656 issued Dec. 6, 1994 describes a throat sponge which may be pre-hydrated which is made from polyvinyl acetal that is fast working and expands instantly and uniformly to absorb 23 to 27 times its weight in fluids.
The present invention solves the above noted problems with tampons in a manner not disclosed in the known prior art.